Merge pull request #3005 from matrix-org/erikj/fix_cache_size

Fix bug where state cache used lots of memory
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Erik Johnston 2018-03-19 11:44:26 +00:00 committed by GitHub
commit 3f961e638a
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2 changed files with 16 additions and 5 deletions

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@ -132,9 +132,13 @@ class DictionaryCache(object):
self._update_or_insert(key, value, known_absent) self._update_or_insert(key, value, known_absent)
def _update_or_insert(self, key, value, known_absent): def _update_or_insert(self, key, value, known_absent):
entry = self.cache.setdefault(key, DictionaryEntry(False, set(), {})) # We pop and reinsert as we need to tell the cache the size may have
# changed
entry = self.cache.pop(key, DictionaryEntry(False, set(), {}))
entry.value.update(value) entry.value.update(value)
entry.known_absent.update(known_absent) entry.known_absent.update(known_absent)
self.cache[key] = entry
def _insert(self, key, value, known_absent): def _insert(self, key, value, known_absent):
self.cache[key] = DictionaryEntry(True, known_absent, value) self.cache[key] = DictionaryEntry(True, known_absent, value)

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@ -154,14 +154,21 @@ class LruCache(object):
def cache_set(key, value, callbacks=[]): def cache_set(key, value, callbacks=[]):
node = cache.get(key, None) node = cache.get(key, None)
if node is not None: if node is not None:
if value != node.value: # We sometimes store large objects, e.g. dicts, which cause
# the inequality check to take a long time. So let's only do
# the check if we have some callbacks to call.
if node.callbacks and value != node.value:
for cb in node.callbacks: for cb in node.callbacks:
cb() cb()
node.callbacks.clear() node.callbacks.clear()
if size_callback: # We don't bother to protect this by value != node.value as
cached_cache_len[0] -= size_callback(node.value) # generally size_callback will be cheap compared with equality
cached_cache_len[0] += size_callback(value) # checks. (For example, taking the size of two dicts is quicker
# than comparing them for equality.)
if size_callback:
cached_cache_len[0] -= size_callback(node.value)
cached_cache_len[0] += size_callback(value)
node.callbacks.update(callbacks) node.callbacks.update(callbacks)